Needle Beam Made from Surface Plasmons

There are many technologies vying for the chance to replace electronics but each of these have challenges to overcome first. Among these technologies is optoelectronics which has to succeed such issues as the size limits of light and the tendency for wave to diffract as they travel. Plasmons can solve the former problem as the quasiparticles, which form from a coupling of photons and conducting electron, are able to exist at the nanoscale and now researchers at Harvard University and the Laboratoire Interdisciplinaire Carnot de Bourgogne in France have addressed the latter challenge.

The researchers created what they are calling a needle beam, which resulted from the interference of two other plasmon beams on a gold foil. Cut into the foil were special grooves with a certain angle to direct the beams towards their intersection. The interference between the two beams left only a single beam that was able to travel over a relatively long distance in a straight line, without any diffraction.

This discovery could be quite important for optoelectronics as it gives a way to transmit a signal with very little signal-loss due to diffraction. Potentially we could see this employed in future computers that are able to operate much faster while using less energy, as photons are able to travel faster and with less resistance than electrons.